Radial or mixed-flow compressor diffuser having vanes

Abstract

The invention relates to a vane (10) of a diffuser (5) for a radial or mixed-flow compressor (2) of an engine (1), including a leading edge (11) arranged facing a flow of gas, a trailing edge (12) being opposite the leading edge (11), a side upper surface wall (13) and a side lower surface wall (14) which connect the leading edge (11) to the trailing edge (12), and a profile including a curved line (15) having at least two points of inflection (I1, I2) between the leading edge (11) and the trailing edge (12). The invention also relates to a corresponding radial diffuser (2).

Description

FIELD OF THE INVENTION[0001]The invention relates generally to gas turbine engines, and more particularly to a diffusion stage of a radial or mixed-flow compressor of a gas turbine, as well as to an associated compressor.TECHNOLOGICAL BACKGROUND[0002]A compressor includes one or more rotating discs (rotor or wheel), bladed or not, and one or more wheels with fixed vanes (straightener stages).[0003]A radial (or centrifugal) compressor has at least one radial compressor stage, that is capable of achieving a flow of gas perpendicular to the central axis of the compressor. It includes at least one wheel with radial blades which aspirate the air axially which, under the influence of the radial force, is accelerated, compressed and driven out radially. This air is then straightened in a diffuser (fixed vanes) which transforms part of its speed into static pressure by slowing the gases leaving the wheel. The operation must take place with a minimum of total pressure loss while still mainta...

AI Technical Summary

Benefits of technology

The invention proposes a diffuser for a compressor that can improve the compressor's efficiency and slow down the flow from the compressor wheel while still maintaining stability. This is achieved by a vane design with a curved profile that includes inflection points. The vane's profile is designed to match the curve of the inner and outer walls of the compressor, leading to better flow control and improved performance.

Problems solved by technology

However, deflection of the air flow leaving the wheel by the vanes of the diffuser can cause separation of the fluid on the intrados or the extrados of the vanes, which separation, if it is considerable, can lead to stalling of the fluid and, as a result, of pumping.

It is known that this pumping phenomenon is harmful to the elements constituting the compressor, so that one seeks to avoid it to the extent possible.

However, these vanes have a limitation in terms of diffusing capacity.

Indeed, an increase in diffusion by these vanes causes a drop in isotropic efficiency and an increase in the instability of the compressor.

However, the use of such a vane showing such an “S” profile requires limiting the cross-section at the diffuser throat (that is at the fluid entry cross-section).

Here too, the cross-section at the diffuser's throat must therefore be limited, which has the effect of reducing the stability of the diffuser.

Images